import sympy

x = sympy.Symbol('x')
a = 0
b = 1
f = x

integral_result = sympy.integrate(f, (x, a, b))
# 这里只是简单示意中值，实际求解中值可能需要更复杂的数值方法
mid_point = (a + b) / 2
print("∫ from {} to {} of {} dx = {}".format(a, b, f, integral_result))
print("Mid - point value: f({}) = {}".format(mid_point, f.subs(x, mid_point)))